Converting Character in an array to an Integer

Swift doesn't make it easy to convert between primitive and typed representations of things. Here's an extension that should help in the meantime:

extension Character {
    func utf8Value() -> UInt8 {
        for s in String(self).utf8 {
            return s
        }
        return 0
    }

    func utf16Value() -> UInt16 {
        for s in String(self).utf16 {
            return s
        }
        return 0
    }

    func unicodeValue() -> UInt32 {
        for s in String(self).unicodeScalars {
            return s.value
        }
        return 0
    }
}

This allows you to get pretty close to what you want:

let container : Array<Character> = [ "a", "b", "c", "d" ]
/// can't call anything here, subscripting's also broken
let number = container[2]
number.unicodeValue() /// Prints "100"

For any engineers that come across this question, see rdar://17494834

I am not sure that it is effective or not but at least it worked. I converted Character to String then to Int.

String(yourCharacterInArray).toInt()

You may try this:

var container = "$0123456789"
var number:Int = Array(container.utf8).map { Int($0) }[3]

It's totally ugly, but it does the job. Also it is a bit computational expensive (O(n) each time one access a character in a string). Still this can be a trick to get back a way to build the CStrings:

typealias CString = Array<CChar>
func toCString(string: String) -> CString {
    return Array(string.utf8).map { CChar($0) } + [0]
}
var cString = toCString("$ 0123456789")
println("The 2nd character in cString has value \(cString[1])") // It outputs 32

or without implementing a function:

var container = "$ 0123456789"
var containerAsCString = Array(container.utf8).map { CChar($0) } + [0]
println("The 2nd character in container has value \(containerAsCString[1])") // It outputs 32

Why not just convert the character to String, get the unicodeScalars for it and extract the .value on the scalar?

something like:

var chr: [Character] = ["C", "B", "A"]

for a in String(chr[1]).unicodeScalars {
    println(a.value)}

For me worked something like:

"\(container[3])".toInt()

Why not just for loop the array and convert everything to Int?

https://developer.apple.com/Library/mac/documentation/General/Reference/SwiftStandardLibraryReference/index.html